May I add some clarification to the question, so as to correct some misleading marketing misuse of the term "directional" in the promotional releases to investors.
- the current DBS technology by Medtronic has 4 electrical sources space linearly on the lead; some degree of variation among the inputs allows tailoring of the stimulation field in the longitudinal direction along the lead, but in the circumferential direction the field is constant; in addition, Medtronic's newer Activa system allows setting up groups of such settings to be used by the patient at home
- the BS Vercise, from the limited documentation released, allows more contacts longitudinally to be programmed independently ... but still no circumferential variation
- the Aleva Neutronics (Swiss university project) literature talks for the first time about a device with an array of sources allowing directional (circumferential) variation. I assume that the human patient testing in the reference article is being performed only in Europe
In another dimension, newer studies recognize that the Parkinson brain has a fluctuating resistance to the electric current, hence Adaptive field sensing and shaping may have benefits.
My concern in seeing such logical enhancements of the technology has already been voiced in previous posts on this forum:
a. does the neurologist know enough about the location of various functional locations in the Subthalamic Nucleus for each PD symptom to be able to tailor the field successfully?
b. what percentage of DBS teams in the US today have the training and are willing to take the time to go beyond just monopolar settings?
c. alternately, what teaming of a knowledgeable patient and programmer would allow for a "trial and error" adaptive convergence process in the long run? and for "as needed" adjustments to the fluctuations?
d. what insurance policy would allow the increased number of visits required to apply the technology.... over repeated far away hospital sessions, or possibly via telemedicine implementations? Until the question a) above can be answered, I don't see how the marketing literature can boast of computer controlled adjustments.